"I can come to no other conclusion," Jack replied. "You must understand that Anstruther is a kind of a specialist in crime; he has frequently been consulted by the police, and, I believe, has brought off some wonderful results. He has even written a book on the subject. Now, we know Anstruther to be an unscrupulous rascal. The police looked upon him as a brilliant aid to themselves. If a man like this chooses to play the part of a criminal Dupuin, see what marvelous opportunities he has. He knows everything about the movements of the police; he can anticipate all their schemes. It is as if Bates himself had turned burglar. Whatever Mrs. Montague might say, it is pretty certain that the embroidered scarf belongs to Anstruther. Quite inadvertently he left it at Lord Longworth's last night, where he was passing in the crowd as an invited guest."
"I know that sort of thing is done," Rigby said. "A very impudent example came under my notice the other day. The thing is much easier done than one would imagine."
"Do you mean to say," Jack asked, "that it is possible for a gentlemanly scoundrel to walk into the house of some great society lady giving a reception, and not be spotted immediately for what he is? It seems absurd!"
"Not a bit of it!" Rigby replied. "To the audacious everything is possible. Supposing a duchess is giving a reception. She has asked perhaps a thousand guests. Half-way through the evening she is so tired and worn out that she does not know or care to whom she may be speaking. Here is the chance for the gentlemanly swindler we are talking about. Of course he is perfectly dressed; he has the most exquisite manners. He lounges up to his hostess, and, after the usual greetings, makes some confidential remark about some friend of the family, which immediately stamps him as one of a certain set. All he has got to do now is to saunter along as if the whole place belonged to him, and help himself to such costly trifles as his mind inclines to."
"Did you ever know of a case in point?" Jack asked.
"My dear chap, I not only know of a case, but I was more or less party to it. It was done for a bet, and I was one of the losers. It was so easily managed that I should not in the least mind trying it myself."
"Well, it seems very odd to me," Jack murmured. "Still, if you know it has been done, there is an end of it."
"Well, it has been shown pretty conclusively," said Rigby, "that Anstruther must have been there last night."
"Quite so," Jack went on. "At any rate the scarf was left behind. I recognized it as soon as ever I saw it in Bates's hand; therefore I was absolutely sure that Anstruther had been at the reception. That is why I suggested that paragraph in the Planet. It is just the sort of silly gossip that papers publish after a sensational crime, and is calculated to hamper the police more than help them. I felt quite sure that somebody or other would bring that paragraph to Anstruther's notice, and that he would lose no time in trying to recover the scarf. I dare say there are other scarves like it in existence, but they are not so common that Anstruther could afford to take any risk. That he realized the gravity of the situation is proved by the fact that he has lost no time in calling at Lord Longworth's to recover the missing property. I think I have made my case very clear."
"Nothing could be clearer," Rigby replied. "Anstruther is at the bottom of this business. I should say he is the cleverest rascal in London at the present moment. And mark the cunning of the beast. Don't you see how easy he can prove an alibi? If he were met face to face now, and taxed with the fact that he was at Lord Longworth's last night he would politely deny it, and, if pressed, have not the slightest difficulty of demonstrating that he was elsewhere."